Mount for electron devices



' Oct. 15, 1929. P. 1''. WEEKS 1,731,282

MOUNT FOR ELECTRON DEVICES Fil ed Nov. 29. 1922 9 v INVENTC)R' 6 PAUL 7:war/(s- 27 ATTORNEY Patented Oct. 15, 1929 UNITED STATES PATENT OFFICEPAUL THORNE HEIRS, OF CALDWELL, NEW JERSEY, ASSIGNOR TO WESTINGHOUSELAMP COMPANY, A CORPORATION OF PENNSYLVANIA MOUNT FOR ELECTRON DEVICESApplication filed November 29, 1922. Serial No. 603,891.

This invention relates to the manufacture of electron devices and moreparticularly to radio tubes and the like.

, An object of the invention is to provide an electron device having theelements so supported and disposed with relation to each other thatbetter electrical characteristics are attained with a reduction in themicrophonic effect.

Another object is to provide a mount for an electron-emission devicewhich will be compact and facilitate the assembly and mounting of thecomponent parts thereof.

A further object is to provide a tube in which an effective relationbetween a grid, a plate and a filament is obtained.

Other objects -and advantages will be apparent from the followingdescription.

The invention may advantageously be embodied in electron-emissiondevices of the type employed with radio equipment. Devices of the abovecharacter usually comprise a bulb having a mount sealed therein, thebulb being evacuated by any suitable means. Such devices are known inthe art as radio tubes or radiotrons. The mount, which constitutes theinternal construction of a radio tube, may comprise a cathode orfilament positioned within a grid, the grid being surrounded by an anodeor plate. These three ele ments are usually held in given relativepositions by support members and byrelatively rigid leading-in wiresembedded in a press; namely the compressed portion of one of thecomponent parts of the mount termed the flare tube.

It is of considerable importance, when manufacturing radiotrons., tohave a struc ture which will facilitate the proper positiona relation.

ing of the elements in a desired relation and for efiicent service ofthe device under practical working conditions, it is desirable toposition the elements in a symmetric spaced Various types of radiotronsor radio tubes have been used. For instance, that in which the plate andgrid are rectangular in cross section in the three planes.

With this type, the filament has usually been in the form of a V or a Wand is supported at three or more points.- The plate and grid actuallyor in effect, operate" as plain rectangular surfaces parallel to theplane of the filament. Another type of a radio tube is that in. whichthe grid and plate are concentric cylinders, the filament being disposedalong their common axis and supported at the ends only.

It is known that, with a given filament and a given spacin between thefilament and grid and the gri and plate, better electricalcharacteristics are given by the cylindrical construction than by theparallel plane construction. It is also known that in order to securegood characteristics with the parallel plane construction, the clearancebetween the elements must be much less than with the cylindricalconstruction. From this it will be understood that a cylindrical orconcentric arrangement of the elements is desirable.

It has been found, however, that when a long filament is mounted in thecylindrical construction, it is essential to employ resilient members tosupport and maintain the filament taut in order to prevent breaking andsagging. A filament so supported is apt to or. rectangular constructioninvolves the ar-- *rangement of the elements with such small clearancespaces between them that the as-' sembly of the elements is extremelydiflicult.

In the present invention the above disadvantages are avoided and arelatively long filament may be employed. Good results have beenobtained by arranging a filament in angular or inverted V-shapesupported at the ends and at the middle point or vertex of the angle.The plate and grid may be formed in the shape of flattened truncatedcones. The plate may be provided with suitable lugs or projections forattachment to support members and the filament and grid may also be ofthe tube, they may be rounded out or separated somewhat at the middle togive greater clearance for the supporting wires. By reason of th1s bulgeor increase of the cones, 1t

. will be evident that more room may be had for the disposition of thegrid over the filament and of the plate over the grid. The operation ofmounting the elements is thus greatly facilitated.

The invention will be more fully understood by reference to theaccompanying drawing in which,

Fig. 1 is a side view in elevation of a radio tube'having a mounttherein embodying my invention;

Fig. 2 is an end elevational view of the mount shown in Fig. 1;

Fig. 3 is a plan view of the angular filament;

Fig. 4 is a view in elevation of the filament shown in Fig. 3; v

Fig. 5 is a plan view of the grid;

Fig. 6 is a view in elevation of the grid shown in Fig. 5; I Fig. 7 is aplan view of the plate;

Fig. 8 is a view in elevation of the plate shown in Fig. 7; and,

Fig. 9 represents, diagrammatically, the

relative positions of the grid and plate at.

their circular portions and the position ofthe filament with respectthereto.

As illustrated, the invention may comprise a mount 1 including a flaretube 2 provided with the usual flare press 3 in which are embodiedsupport wires 4 and 5, to which a plate 6 may be welded or otherwisesecured. Ears 7 and 8, to which the support wires 4 and 5 mayrespectively be fastened, are provided on the plate." The support wire 5may have a lead-in wire or conductor 9 connected thereto.

Disposed within the plate, is a grid 11 welded or otherwise secured to arelatively rigid support wire 12, which is also embedded in the press 3and may have connected thereto a leading-in wire or-conductor 13. Alooped filament 14:, which preferably consists of an angular or invertedV-shape wire, may be disposed within the grid and with the legs orstraight portions 15 and '16 thereof, disposed in a given symmetricrelation tothe sides of the grid. The filament may be supported at itslower ends by welding or otherwise securing to support wires 17 and 18,

which may also be connected with leading-in conductors 19 and 21respectively.

A third filament support member 22 secured'in the press 3 may extenddirectly to the vertex of the filament or may be, offset from the pressand extend upwardly above the plate andbe connected by a flexiblesupport 31 to the vertex of the filament to aid in maintaining it in agiven position on the mount.

The wires of the conical helix comprising thegrid, are preferably heldtogether by a stiffening bar 29 which may be welded to the sup portmember 12 for securing the grid in place.

The filamentmay be so proportioned as to be symmetrically spaced fromthe grid when the elements are intheir operative positions.

The effective portions of the grid and plate being the circular ones, itis desirable to properly dispose these surfaces with respect to eachother and by the use of a V-shaped filament together with the peculiarlyshaped grid and plate, a construction is provided whereby the filamentmay be supported in a practical and efficient manner and, at the sametime, the greater portion of the filament will be disosed in effectiverelation, that is, substantialy at the centers of the circular portionsof grid and plate as shown in Fig. 9 in which the filament 14' is showncentrally disposed with respect to the circularly curved portions 27 ofthe grid and 24 of the plate.

Where desirable, the circular portions 23 and 24 of the plate and thecircular portions 26 and 27 of the grid may be connected by arcuateportions which bulge outwardly from their axial line to a greater orless degree, as desired. This allowance provides for the more convenientpositioning of the elements during the mounting operation.

When a radiotron mount is to be manufactured, the filament 14 isproperly positioned and secured to the support members 17 and 18. Thegrid 11 may then be placed over the filament in the proper plane andadjusted by moving the grid axially until the filament legs 15 and 16are substantially at the centers of the circular portions 26 and 27 ofthe grid which may then be secured to the support member 12. Finally theplate is symmetrical- 1y disposed about the grid and secured to thesupportwires 4 and 5.

When the several elements have been thus ositioned, the upper end orvertex of the amentmay be secured or hooked upon a.

proportions of the elements. Also, it will bev seen that the filamentmay be so disposed that practically its entire length is made effective,since its position approaches the ideal with respect to the grid andplate, the'axial line of the legs of the filament being so disposed asto coincide with the axis of the semi-circular portions of the grid andplate.

The peculiar tapering shape of the elements as employed in my inventionmakes it possible to more readily adjust them to obtain a symmetricspaced relation. Where a filamentisin place, it will be seen that thegrid may be placed thereover and, by an axial adjustment of the grid, agreater or lesser space may be provided. The same is'true with respectto the plate when disposed over the grid.

It will therefore be evident that not only may the desired spacedrelation be conveniently lad but the distances between the elements maybe adjusted without altering the symmetrical relation of the elements.

With the above construction, a mount is provided in which the mosteffective portions of the elements are utilized and in which thetendency toward microphonic efiects isgreatly reduced.

Although I have shown and described the preferred embodiment of myinvention, it is to be understood that modifications may be made thereinwithout departing from the spirit and scope of the appended claims.

What is claimed is:

1. A mount for: an electric device comprising an angular filament, agridof flattened truncated cone shape disposed about said filament, aplateof truncated cone shape disposed about said grid, the legs of saidfilament being disposed in uniform spaced relation to the inner surfaceof said grid.

2. A mount for an electron device comprising a filament of invertedV-shape, a grid of flattened truncated cone-shape disposed about saidfilament and a plate of flattened truncated cone-shape disposed innested spaced relation to said grid.

3. A mount for an electron device comprising a filament ofinvertedV-shape, a grid having sections in the form of partial cylindersconnected by substantially flat portions and so disposed about saidfilament as to position said filament substantially concentric to saidpartial cylindrical portions and a plate similarly shaped butproportionately larger than said d to permit its being positioned aboutsaif g rid and in a symmetric spaced relation thereto.

4. A mount for an electron device comprising a filament of invertedV-shape, a grid having portions in the form of partial cylindersconnected by substantially flat portions and so disposed about saidfilament as to position the filament in symmetrically spaced relation tosaid partial cylindrical portions, and a plate having partialcylindrical portions connected b straight portions and so disposed aboutsaid grid that the partial cy- ,lindrical portions of said plate areconcentrically disposed with respect to the partial cylindrical portionsof said grid.

5. A mount for an electron device comprising a grid consisting of a coilwhich uniform- .ly increases in size from ehd to end and is of elongatedcurved transverse cross section, a plate comprisin a hollow body ofsimilar shape but of su ciently greater dimensions than the grid, sothat said plate may be dis-- posed about said grid and symmetricallyspaced therefrom and a filament so disposed as to pass substantiallythrough the centers of the curved end portionsof said grid and plate. Y

6. A mount for an electron device comprising a filament of invertedV-shape, a .grid having sections of relatively small radii connected bysubstantially straight portions and so disposed about the filament as toposition the legs of said filament upon the axial line of said sectionsand a plate having substantially partial cylindrical portions connectedby substantially straight portions disposed about said grid with theaxial lines of said partial cylindrical portions coincident ,with theaxial lines of the legs of said filament.

7. A mount for an electron device comprising a filament of invertedV-shape, a tapering I grid having sections of relatively small radiiconnected by relativel flat portions and so disposed about said ament asto position said filament substantially concentric to said sections anda plate similarly shaped, but proportionately larger than said grid, topermit its being positioned. about said grid and in a desired spacedrelation thereto.

In testimony whereof, I have hereunto subscribed my name this 28th dayof November 1922.

PAUL THORNE

